Vibrationally resolved photoelectron imaging of platinum carbonyl anion Pt(CO)_n - (n 1-3): Experiment and theory

摘要

Photodetachment of platinum carbonyl anions Pt(CO)_n - (n 1, 3) had been previously investigated using traditional photoelectron spectroscopy (PES) [G. S. Icking-Konert, H. Handschuh, G. Gantef?r, and W. Eberhardt, Phys. Rev. Lett. 76, 1047 (1996)10.1103/PhysRevLett.76.1047; B. Chatterjee, F. A. Akin, C. C. Jarrold, and K. Raghavachari, J. Chem. Phys. 119, 10591 (2003)]10.1063/1.1619131. Here, we studied Pt(CO)_n - (n 1-3) using photoelectron velocity-map imaging method and extensive theoretical calculations. Vibrationally resolved spectra from photoelectron imaging experiments allow determination of the electron affinities of Pt(CO)_n, which are 1.196 ± 0.034, 0.930 ± 0.042, and 1.253 ± 0.032 eV for n 1, 2, and 3, respectively. Two vibrational progressions are resolved for the ground states of Pt(CO) and Pt(CO) _3, while only one is resolved for that of Pt(CO)_2. The frequencies are determined to be 2089 ± 91 and 581 ± 21 cm ~(-1) for Pt(CO), 2173 ± 115 cm~(-1) for Pt(CO) _2 and 2119 ± 88 and 444 ± 18 cm~(-1) for Pt(CO)_3. Results from density functional theory and ab initio calculations agreed well with the experimental observations. The spectra were well reproduced by Franck-Condon fitting on the basis of the optimized geometries and the theoretical frequencies. The well-resolved PES also provided valuable benchmarks for various density functionals (B3LYP, BP86, and PW91PW91) for the platinum carbonyls.